C语言深度解析--结构体

从0到1：JavaScript快速上手第六章课后习题 

编程思路，先正序排序，然后再将排序结果倒叙。

其实就是想用sort函数和reserve函数 

        var arr=[3,9,1,12,36,50,21]
        var up_arr = arr
        up_arr.sort(function(a,b){
            return a - b
        })

        document.write("排序后的数组:" + up_arr + "<br>")
        document.write("最小值:" + up_arr[0] + "<br>")

        up_arr.reverse()
        document.write("reverse后得到最大值:" + up_arr[0] + "<br>" + "<hr>")


        var down_arr = arr
        down_arr.sort(function(a,b){
            return b - a
        })

        document.write("排序后的数组:" + down_arr + "<br>")
        document.write("最大值:" + up_arr[0] + "<br>" + "<hr>")

执行结果：

        var colors=["red","green","blue"];
        colors[1]="yellow";
        document.write(colors)//red,yellow,blue

 解析

代码：

        function my_reverse(str){
            document.write("原始字符串:" + str + "<br>")
            var str_arr = str.split("")
            str_arr.reverse();
            return str_arr.join("")

        }
        document.write("颠倒后的字符串:" + my_reverse("hello") + "<br>")
        document.write("颠倒后的字符串:" + my_reverse("world") + "<br>")